CT aorta is a radiographic diagnostic technique that allows to obtain an image of sections of various parts of the aorta and its branches to assess the state of the vascular walls, identify the localization and prevalence of pathological changes. The angioscanning zone may include the thoracic, abdominal or aorta throughout. CT is indicated for suspected aortic aneurysm (including dissection, wall ruptures, hematomas, thrombosis), tumor compression, congenital anomalies, stenosis and occlusion of branches, as well as for planning and monitoring angiosurgical treatment. The study is performed with additional X-ray contrast enhancing the sharpness of the vascular image on the slices.
Indications
CT aorta is performed for inflammatory, destructive, atherosclerotic, tumor lesions. The procedure is indicated for suspected aneurysmal dilation, aortic dissection, thrombosis, embolism, inflection, narrowing of the lumen due to stenosis or occlusion as a result of the cicatricial-adhesive process. CT-aortography is performed during preoperative examination of patients to plan the volume of surgical intervention on the arterial trunk. The technique is used to monitor the course of the operation, follow-up in the postoperative period, as well as to assess the condition of the stent or prosthesis.
CT of the abdominal aorta is prescribed in order to obtain a three-dimensional image of the vessels of the abdominal cavity: the aorta, the abdominal trunk, the renal and inferior mesenteric arteries, the splenic artery in order to visually assess the structure and condition of the vascular system. CT of the abdominal aorta is informative for tumor processes in order to detect mesenteric and paraaortic metastases to lymph nodes and vessels or for anomalies in the development of the aorta and its branches (fibromuscular dysplasia of the renal arteries, malformations, etc.), atherosclerotic changes.
Indications for CT of the thoracic aorta are aortic coarctation, an open duct between the aorta and the pulmonary artery, atherosclerosis of the vessels, stenosis of the aortic mouth. Scanning is performed to detect aortitis (tuberculous or syphilitic), tumor processes in the walls of blood vessels, including during the germination of neoplasms from the mediastinal organs.
Contraindications
Computed tomography is contraindicated for pregnant and lactating women, as well as children under 14 years of age, since even a minimal radiation load can harm the fetus and the growing body. If it is necessary to perform CT, breast-feeding women should stop feeding on the day of manipulation and resume two days after it is performed. Performing CT-aortography is difficult in patients with intense pain syndrome, hyperkinesis, since such patients may have involuntary movements during the procedure, which significantly reduces the quality of the images.
It is impossible to perform CT in patients weighing more than 120 kg due to technical limitations of the tomograph design (only in some modern scanners the weight load is designed for a weight of 200 kg). Diagnosis with contrast is not prescribed to patients with severe kidney damage due to the poor rate of excretion of the drug and the possibility of toxic complications. In case of iodine intolerance, a contrast study is not carried out to exclude allergic reactions. Manipulation is also contraindicated in case of a risk of exceeding the dose of X-ray radiation as a result of previous radiation studies.
Preparation
CT aorta is performed in a round-the-clock hospital or outpatient. Before scanning, an iodine-containing contrast agent is injected intravenously through a catheter, which, when it enters the blood, stains the vessels. This makes it possible to better visualize the aorta on tomograms. Contrast is non-toxic and is completely eliminated from the body in a few days. Diagnosis is carried out on an empty stomach, 5-6 hours before it is performed, the patient is forbidden to eat. No other preparation for the study is required. It is necessary to have the data of previous examinations, the referral of the attending physician on hand.
Methodology of conducting
During CT scan of the aorta, the subject is motionless, is in a horizontal position on the mobile “couch” of the tomograph. His body is fixed with special rollers in order to exclude accidental movements and obtain an optimal image. The procedure itself takes no more than 30 minutes, during which the patient is automatically moved through the tunnel of the device, while a magnetic ring rotates around the mobile table along a given trajectory, and the scan results are transmitted to the monitor. The introduction of contrast is accompanied by a feeling of warmth throughout the body, crackling is heard during the operation of the tomograph. Manipulation does not cause other sensations. The tomograph is shielded, only the patient is in the scanning room. A doctor or a laboratory assistant monitors the progress of CT from an adjacent room, communicating with the patient through a microphone mounted in the tunnel ring. The results are handed out within 40 minutes.
The conclusion on the diagnosis with a description of the results of CT-aortography is made by a diagnostic doctor. It is given to the patient in his hands together with the pictures taken on a maxi-format film. The absence of pathological changes in the structure of the main vessel is regarded as the norm, in other cases, with the results of CT aorta, the examinee should contact his attending physician, who will diagnose and develop tactics for further management. If necessary (for vital indications), emergency hospitalization is carried out.
